TRICARE and Medicare: How the Two Work Together at 65
If you are a military retiree (or the spouse or child of one) and you are turning 65, you need Medicare Part A and Part B to keep your TRICARE coverage. Once you have both, TRICARE For Life (TFL) becomes your second payer. Medicare pays first, TFL picks up most of what is left, and for services both programs cover you usually owe nothing. You do not sign up for TFL. It starts on its own when Part A and Part B take effect.
That is the short version. The details are where people get tripped up: the Part B deadline, the premium you still pay, what changes if you choose a Medicare Advantage plan, and whether Part D is worth adding. This guide walks through each one using TRICARE’s own published rules.
TL;DR
- At 65, retirees and their eligible family members must have both Medicare Part A and Part B to keep TRICARE. Drop or miss Part B and you lose TRICARE.
- TRICARE For Life has no enrollment form. It begins automatically when your Part A and Part B are effective.
- With Original Medicare, Medicare pays first and TFL pays second, which leaves you with $0 out of pocket in most cases for services both cover.
- You can keep TFL with a Medicare Advantage plan, but claims no longer cross over automatically and you may have to file for TRICARE reimbursement yourself.
- Part D is optional. TRICARE has its own pharmacy benefit.
Table of Contents
- How TRICARE and Medicare divide the work
- Why Part B is not optional
- What TRICARE For Life costs
- Original Medicare with TFL
- Medicare Advantage and TRICARE
- Prescriptions: do you need Part D?
- Other insurance, opted-out providers and the VA
- A short checklist before you turn 65
- Getting local help with the decision
- FAQ
- Sources
How TRICARE and Medicare divide the work
Medicare is the federal health program for people 65 and older and for some younger people with disabilities. TRICARE is the health program for uniformed services members, retirees and their families. They are separate programs with separate rules, and at 65 they stop being alternatives and become partners.
TRICARE describes TFL as Medicare-wraparound coverage. Medicare processes the claim first. It then forwards the claim to TRICARE, which covers the remaining coinsurance and deductibles. The Defense Health Agency designed it so that a service covered by both leaves you owing nothing.
Two points follow from that design:
- TFL only works on top of Medicare. TFL covers people who are TRICARE-eligible and have Medicare Part A and Part B, regardless of age or where they live.
- When only one program covers a service, normal cost-sharing for that program applies. The $0 result is for services covered by both.
Why Part B is not optional
This is the rule that costs people the most. If you are eligible for premium-free Part A and you are a retiree or a family member of one, you must have Part B to keep TRICARE, even if you live overseas. You lose TRICARE if you never sign up for Part B, if you drop it, or if you stop paying the Part B premium.
TRICARE also says some people do not need to have Part A, namely those who can show they are not eligible for premium-free Part A. Check TRICARE’s turning 65 page for what proof is required.
Timing your Part B enrollment
Officials advise enrolling in Part B at least two months before your 65th birthday, so that processing delays do not leave a gap in coverage. A gap in coverage is the real danger here. Because TRICARE ends without Part B, a late Part B start can leave you with neither program paying for a while.
Miss your initial window and a late-enrollment penalty for Part B may apply. Our guide to Medicare enrollment periods explains how the seven-month initial window works, and our piece on the Medicare late enrollment penalty shows how penalties build.
A simple timeline
- About three months before your 65th birthday: your initial enrollment period opens. Confirm your Part A status and sign up for Part B.
- At least two months before the birthday: this is TRICARE’s recommended deadline for Part B, to avoid a break.
- Month you turn 65: Medicare coverage starts. TFL starts the same day your Part A and Part B take effect.
- After you are covered: carry your Medicare card and your Uniformed Services ID card. Together they are your proof of coverage.
What TRICARE For Life costs
There is no TFL enrollment form and no TFL-specific card. Your Medicare card and Uniformed Services ID card are your proof of coverage, so there is no welcome packet to wait for.
What you do keep paying is the Part B premium. CMS set the standard 2026 Part B premium at $202.90 a month, up from $185.00 in 2025. Higher-income households can pay more. CMS publishes the 2026 amounts, and the 2027 figures are normally announced in the fall, so check them before you budget.
That answers a question many readers ask: do I need to pay for Medicare if I have TRICARE? If you are a retiree at 65, yes, the Part B premium is the price of keeping TRICARE. Your TFL coverage itself comes without a separate enrollment fee.
Original Medicare with TFL
This is the simplest setup and the one most military retirees use. The claim flow looks like this:
| Step | What happens |
|---|---|
| 1 | Your provider bills Medicare. |
| 2 | Medicare pays its share. |
| 3 | Medicare forwards the claim electronically to TFL. |
| 4 | TFL pays the remaining coinsurance and deductible for TRICARE-covered services. |
| 5 | You usually owe nothing for services both programs cover. |
Because the crossover is automatic, you rarely handle paperwork. The tradeoff is that Original Medicare has no out-of-pocket cap on its own, and TFL is what supplies the protection.
One point worth knowing: you do not need a Medigap policy for this. TFL already fills the gap that Medigap would otherwise fill, so most TFL beneficiaries do not buy one. If you want to compare how Medigap works for people without TRICARE, our Medicare Supplement guidance covers it.
Medicare Advantage and TRICARE
People search for “TRICARE For Life vs Medicare Advantage” as if it were an either-or choice. It is not. You do not lose TFL if you enroll in a Medicare Advantage plan. TFL keeps acting as second payer for TRICARE-covered services.
What changes is how the claims move. Medicare Advantage plans are an all-in-one alternative to Original Medicare, run by private companies, and some include extras such as dental or vision. But with Original Medicare the system forwards the leftover balance to TFL automatically. With a Medicare Advantage plan, you must file paper claims with the TFL contractor, Wisconsin Physicians Service, for remaining TRICARE-covered services. That adds work for you.
Original Medicare plus TFL or Medicare Advantage: how to decide
| Question | Original Medicare + TFL | Medicare Advantage + TFL |
|---|---|---|
| Who pays first? | Medicare | The Medicare Advantage plan |
| Do claims reach TFL automatically? | Yes | No, you file with the TFL contractor |
| Extra benefits (dental, vision) | Not part of Original Medicare | Often included, varies by plan |
| Provider choice | Any provider that accepts Medicare | Depends on the plan’s network and rules |
| Paperwork | Low | Higher |
A Medicare Advantage plan can make sense if the extras matter to you and you are comfortable with the claims work. For many retirees, Original Medicare with TFL is the lower-effort path because the combination already caps most costs. Neither is right for everyone, and the answer depends on your doctors, your prescriptions and the plans sold in your county. If you want help weighing the two, our plan comparison help puts them side by side for your situation.
One more caution on timing: once you join a Medicare Advantage plan, check that it covers the doctors you already see, since the plan rather than Original Medicare is your first payer.
Prescriptions: do you need Part D?
No. A common misconception is that you must join Part D to keep your benefits. TRICARE keeps its own pharmacy benefit, and Part D is optional if you want additional coverage.
Whether it is worth adding depends on which drugs you take and where you fill them. If you already use the TRICARE pharmacy benefit and it covers your medications, Part D may add little. If you take drugs that are expensive or that you fill at a retail pharmacy outside the TRICARE network, it is worth a closer look. Our explainer on how Part D costs and formularies work shows what to compare, and a prescription plan review checks your actual drug list.
If you do add Part D later, a late penalty can apply to people who go without creditable drug coverage. Confirm with the plan whether your TRICARE pharmacy coverage counts before you decide to skip.
Other insurance, opted-out providers and the VA
Three situations produce surprise bills, so know them in advance.
Other health insurance. If you have employer or other coverage on top of Medicare and TRICARE, TFL is always the final payer. It pays only what is left after Medicare and the other insurance process their shares. If you are still working or leaving a job plan, our COBRA versus Medicare guide explains why that decision has its own deadline.
Providers who opted out of Medicare. Such providers cannot bill Medicare. TFL then treats the claim as the second payer, but because Medicare pays nothing, you owe the resulting costs yourself. Opt-out providers can set private contracts with no charge limits, so the bill may exceed standard Medicare and TRICARE amounts. Ask any new provider whether they accept Medicare before your first visit.
VA providers. Department of Veterans Affairs providers also cannot bill Medicare, so the same rule applies to care received there when TFL is asked to pay as second payer.
A short checklist before you turn 65
- Confirm you are TRICARE-eligible as a retiree or family member, and that your Uniformed Services ID card is current.
- Check whether you qualify for premium-free Part A.
- Sign up for Part B at least two months before your birthday.
- Decide between Original Medicare and a Medicare Advantage plan, and if you choose the latter, find out how you will file with the TFL contractor.
- Compare your TRICARE pharmacy coverage against a Part D plan using your real prescription list.
- Ask every provider you use whether they accept Medicare.
Getting local help with the decision
At Almond Insurance, we are a Medicare agency in Rockford, Illinois, serving Northern Illinois and Southern Wisconsin. We explain Medicare in plain language, compare Medicare Advantage, Medicare Supplement and Part D options, and support your enrollment. If you are a first-timer, our new-to-Medicare guidance walks you through each step, and our enrollment assistance can help you get Part A and Part B in place on time. You can see everything we do on our services page. Caregivers helping a parent or spouse are welcome too. TRICARE questions that only the Defense Health Agency or your TFL contractor can answer, such as a specific claim, should go to them directly.
FAQ
Can you have both Medicare and TRICARE?
Yes. In fact, once a retiree or eligible family member turns 65, both are required: Medicare Part A and Part B, with TRICARE For Life paying second. Having both is what produces the low out-of-pocket result.
How much is Medicare Part B if I have TRICARE For Life?
The premium is the same as for everyone else. The standard 2026 amount is $202.90 a month, and higher incomes can pay more. TFL has no separate enrollment form to fill out.
What happens if I do not sign up for Part B?
You lose your TRICARE coverage, regardless of age or where you live, and a Part B late-enrollment penalty may apply. That is why TRICARE advises acting at least two months before you turn 65.
Does TRICARE For Life work with a Medicare Advantage plan?
Yes, you keep eligibility. The difference is that claims do not cross over automatically, so you may need to file with the TFL contractor yourself for remaining TRICARE-covered costs.
Do I need Part D if I have TRICARE?
No. Part D is optional because TRICARE has its own pharmacy benefit. Compare your drug list against both before deciding.
Sources
- Becoming Medicare-Eligible, TRICARE
- TRICARE For Life, TRICARE
- Q&A: How Does TRICARE For Life Work With Medicare?, TRICARE Newsroom
- Retired Service Members and Their Family Members, TRICARE
- I’m turning 65 soon, how do I enroll in TRICARE For Life?, TRICARE
- 2026 Medicare Parts A & B Premiums and Deductibles, CMS
- Will I lose my TRICARE For Life benefits if I sign up for a Medicare Advantage plan?, TRICARE
- TRICARE For Life Handbook
- Beneficiaries Eligible for TRICARE and Medicare, TRICARE
- Does TRICARE For Life Work With Other Insurance?, TRICARE Newsroom
- Turning 65? What you need to know about Medicare and TRICARE For Life, DHA